The gun issue is beginning to wane in voters' minds ahead of the November midterm elections, a new NPR/PBS NewsHour/Marist poll finds.

While almost half of all registered voters (46 percent) say a candidate's position on gun policy will be a major factor in deciding whom to vote for, that number is down 13 points from February, when a shooting at a Florida high school sparked outrage.

So if Democrats are counting on guns to motivate their voters to get to the polls, maybe they shouldn't. There has been a major drop among Democrats on the issue — down 21 points over the past two months. In February, 74 percent of Democrats called it a major factor in deciding their vote in February, but now just 53 percent say so.

The issue has faded among independents, too, dropping from 54 percent to 42 percent who said gun policy would have a major impact on their vote.

"This finding raises a cautionary flag for voters who want gun policy to be front and center this election cycle," said Lee Miringoff, director of the Marist College Institute for Public Opinion. "Still, a majority of Americans, overall, want stricter gun control, support efforts to curb gun violence over gun rights, unlike in the aftermath of Sandy Hook, and believe the Parkland students have already had an impact on the gun reform debate."

Seventeen people were killed in the shooting at a Parkland, Fla., school in February. In December 2012, 26 people, including 20 children, were killed in a shooting at Sandy Hook Elementary School in Newtown, Conn.

As survivors of the Parkland attack plan a national walkout this Friday to coincide with the anniversary of the 1999 mass shooting at Columbine High School in Colorado, most Americans think the teens are having at least some impact.

A third of U.S. adults said the teenagers are having a major impact with their crusade for more gun control, while 46 percent say they're having a minor impact and 18 percent say they're having no impact at all.

Those numbers have risen slightly from two months ago, but almost a quarter of Republicans said the students aren't having any impact with their social media campaigns and organization. Meanwhile, 46 percent of Democrats do say the Parkland students are having a major impact.

Overall, most voters still say controlling gun violence outweighs protecting gun rights by a 19-point margin, 57 percent to 38 percent. Those numbers are divided along partisan lines, with 81 percent of Democrats saying it's more important to find a way to stop gun violence.

But there are some mixed views among GOP voters — 62 percent said protecting gun rights should be the priority, but almost one-third do say controlling gun violence should be the most important.

Those numbers have shifted toward safety concerns outweighing gun ownership over the years. Back in March 2013, just months after the deadly Sandy Hook Elementary School shooting, U.S. adults were split on the question.

By October 2017, though, in the wake of a shooting at a Las Vegas music festival that killed 58 people, stopping gun violence over protecting gun rights won out by a 7-point margin. Now, that has more than doubled. And more than half of voters also say stricter gun laws should be an immediate priority in Congress.

Voters also say they would back candidates who want certain gun control measures. By a nearly 2-to-1 margin, voters say they would definitely vote for a candidate who wants stricter gun control laws, with 33 percent saying they would definitely vote against such a candidate.

Eighty-three percent of Democrats and 61 percent of independents would back candidates who want stronger gun laws. Among Republicans, 57 percent would oppose such candidates, while 32 percent of GOP voters do say they would definitely vote for a candidate who wants stricter gun laws.

Some of those specific measures garner more support than others do. Voters are most unified behind candidates who want increased funding for mental health screening and treatment — 91 percent of all voters say they would definitely vote for a candidate who wants such measures. That support is unified across party lines.

There is even broad bipartisan support for requiring background checks for gun purchases at gun shows or through other private sales — 86 percent of registered voters said they would back candidates who want to implement those stricter measures, including 85 percent of Republicans and 83 percent of gun owners.

But other ideas are more divisive, chief among them a plan, which has been endorsed by President Trump, to allow schoolteachers to carry guns. By a 22-point margin, voters say they would definitely oppose a candidate who wants to arm educators (58 percent) versus those who definitely support a candidate who wants to do that (36 percent).

Eighty-one percent of Democrats and 57 percent of independents would oppose candidates who want to arm teachers. Republicans support letting teachers carry guns by a 2-to-1 margin, 60 percent to 30 percent.

Fifty-six percent of voters say they would definitely vote for candidates who want to ban the sales of semi-automatic assault weapons such as the AK-47 or AR-15, while 38 percent say they would vote against a candidate who backs such a proposal.

Nearly three-quarters of Democrats and just over half of independents would also back a candidate who supports an assault-weapons ban. Half of Republicans would oppose a candidate who calls for a ban, but 42 percent of GOP voters say they would definitely vote for a candidate who wants this type of ban.

Just over half of voters (52 percent) say knowing that a candidate has received contributions from the National Rifle Association would spur them to vote against that person, while 36 percent said it would mean they definitely would support that candidate.

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